1. Field of the Invention
The present invention relates to a position detecting device of a moving body and a vehicle door used in a power window device for moving a window glass of the vehicle door for opening and closing this window glass, a sunroof device for moving a sunroof for opening and closing this sunroof, etc.
2. Description of the Related Art
For example, a motor as a drive source is used for a power window device for moving a window glass of a vehicle up and down for opening and closing this window glass, and a sunroof device for moving a sunroof for opening and closing this sunroof.
Here, for example, the power window device has a so-called catch-preventing function which prevents a portion of the body of a vehicle occupant and a foreign object from being inadvertently caught between the window glass and a window frame. In the power window device having the catch-preventing function of such a kind, a limit switch is disposed at a predetermined position of the door. On the basis of signals from this limit switch and the lock electric current of the motor, a determination is made as to whether the foreign object has been caught by the window glass, and the movement of the window glass, i.e., the rotating position of the motor, is controlled appropriately. In another construction of the power window device, the rotational frequency of the armature is detected by providing a Hall IC and a special commutator. On the basis of the rotational frequency detection signal (the number of pulses and the pulse width of the pulse signal), a determination is made as to whether the foreign object is caught, and the rotational position of the motor is controlled.
However, a complicated adjustment of assembling positions of the motor and a window regulator during assembling and a complicated reset after the assembling are indispensable to such a power window device (a rotating position detecting mechanism of the motor). A drawback exists in that parts such as a controller, etc. is expensive and is imprecise when the catch-preventing mechanism must be assembled.
Therefore, the inventors of this application have proposed a position detecting device of a moving body able to solve such a drawback (e.g., Japanese Patent Application Laid-Open (JP-A) No. 8-29114).
In this proposal, the position detecting device has a planetary gear set constructed by a ring gear rotatably held by a cover plate of this device and a planetary gear engaged with this ring gear. The position detecting device also has a switch section constructed by a moving contact integrally formed on the ring gear and rotated together with the ring gear, and fixed contacts fixed to the cover plate and able to come in contact with the moving contact. Otherwise, the position detecting device has a clutch mechanism for cutting off transmission of rotating force from the moving body (a motor output shaft) to the ring gear in a forward rotating direction, etc. Thus, when the position detecting device is used in the power window device and the sunroof device, positions of the window glass and the sunroof can be detected with high precision and movements thereof can be also controlled. Further, initial positions of the window glass and the sunroof can be set without making any complicated adjustment. Furthermore, such contents can be realized at low cost and with a simple structure.
The above position detecting device of the moving body has a function capable of mechanically storing a predetermined reference position of the moving body (a function capable of automatically setting an initial position of the moving body). However, if an assembling state (procedure) into the moving body is incorrect, there is a possibility that the above original function cannot be fulfilled. Therefore, it is possible to improve such a drawback.
Namely, for example, an adjusting procedure of the position detecting device assembled in the power window device will be explained. First, the motor for driving the power window device is once sufficiently rotated in the forward rotating direction when the position detecting device is assembled into a vehicle body. When the motor has reached a predetermined rotating position (a predetermined reference position of the window glass), a state in which the rotation of the ring gear of the planetary gear set is prevented in the forward rotating direction is set. When the motor is further rotated in this state, the transmission of rotating force from the motor output shaft to the ring gear of the planetary gear set in the forward rotating direction is cut off by the clutch mechanism so that only the planetary gear is revolved. An initial state for operating the switch section, i.e., an initial state for mechanically storing the predetermined reference position of the window glass is automatically set by the above-mentioned operation.
However, if this position detecting device is assembled into the vehicle body in a state in which the motor has already reached the predetermined rotating position (in which the window glass has already reached the predetermined reference position), no motor can be sufficiently rotated after that. In other words, no state in which the rotation of the ring gear of the planetary gear set is prevented in the forward rotating direction is set although the motor has reached the predetermined rotating position (in which the window glass has reached the predetermined reference position). Therefore, there is a possibility that no initial state in which the switch section is operated (i.e., no initial state where the predetermined reference position of the window glass is mechanically stored) is set.
For example, techniques relative to the present invention are disclosed in Japanese Patent Application Laid-Open (JP-A) No. 59-77933 disclosing a sensor having a reset knob in a predetermined position of a sensor case, and Japanese Patent Application Laid-Open (JP-A) No. 63-47485 in which a free area for performing no catch-preventing control is set. The techniques relative to the present invention are also disclosed in Japanese Patent Application Laid-Open (JP-A) No. 63-47486 in which a reference position of a position detecting means is reset at a full opening end or a full closing end, and Japanese Patent Application Laid-Open (JP-A) No. 6-6679 disclosing a technique for detecting a releasing area of the catch-preventing control by a window moving sensor. The techniques relative to the present invention are also disclosed in U.S. Pat. No. 4,468,063 disclosing a technique in which a clutch is arranged between a motor shaft and a drive shaft, and the drive shaft and a switch are connected to each other through a cam. The techniques relative to the present invention are also disclosed in U.S. Pat. No. 4,530,185 disclosing a technique in which a switch device is arranged between a motor and a door lock, and an electromagnetic clutch between the motor and the switch device is operated in accordance with a position of the switch device. The techniques relative to the present invention are further disclosed in U.S. Pat. No. 5,174,425 disclosing a technique for simultaneously adjusting each of a steering angle sensor and a steering shaft to a neutral position by the operation of a clutch mechanism disconnected by a pin member of a steering angle detector for a vehicle.